1. Field of the Invention
The present invention relates to novel water-soluble copolymers which comprise, in copolymerized form,    (a) 60 to 99% by weight of at least one monoethylenically unsaturated polyalkylene oxide monomer of the formula IH2C═CR1—X—YR2—OnR3  I     in which the variables have the following meanings:            X is —CH2— or —C(O)—, if Y is —O—;                    is —C(O)—, if Y is —NH—;            is —O— or —O—(CH2)4—, if Y is a chemical bond;                        Y is —O—, —NH— or a chemical bond;        R1 is hydrogen or methyl;        R2 is C2-C4-alkylene radicals, which may be identical or different and also linear or branched, but where at least 50% of the radicals R2 are ethylene;        R3 is C1-C22-alkyl, phenyl, p-(C1-C12-alkyl)phenyl or hydrogen;        n is an integer from 6 to 50,            (b) 1 to 40% by weight of at least one nonquaternized dipolar monomer comprising at least one nitrogen atom,    (c) 0 to 39% by weight of other nonionic monoethylenically unsaturated monomers and    (d) 0 to 10% by weight of other anionic monoethylenically unsaturated monomers    and have an average molecular weight Mw of from 2000 to 500 000 D.
In addition, the invention relates to the use of these copolymers as dispersants and sequestrants for pigmented materials, as additive for detergents, laundry pretreatment agents, cleaners for hard surfaces, dentifrices and bodycare compositions, and as auxiliaries for textile processing, paper making and paper processing and deinking processes.
Last but not least, the invention relates to detergent formulations which comprise these copolymers.
2. Description of the Background
Pigment-containing soilings, in particular those caused by the color-imparting components of tea, coffee and also grass, can usually only be removed with difficulty from textile and hard surfaces. This problem also arises in the area of dental care. In addition, the removal of pigmented materials from substrates is also of importance in industrial processes, such as textile processing, paper making and paper processing, and deinking processes. The compositions used hitherto for these purposes are generally unsatisfactory.
JP-A-1999/208098 describes the use of copolymers of N-vinylimidazoles and methylpolyethylene glycol (meth)acrylates which comprise, in copolymerized form, 90 to 95 mol % of the N-vinylimidazole monomer, as dye receptor for the coating of inkjet papers.
JP-A-1986/26608 discloses aqueous pigment dispersions for paints which comprise, as dispersant, copolymers of 48 or 46% by weight of polyethylene glycol methacrylate or polypropylene glycol methacrylate, 50% by weight of N-vinylpyrrolidone or N-vinylimidazole and additionally 2 or 4% by weight, respectively, of (meth)acrylic monomers comprising quaternary ammonium groups.
JP-A-2001/31885 also describes dispersants for pigments which represent copolymers of N,N-dimethylaminopropylacrylamide or N-vinylimidazole, methylpolyethylene glycol methacrylate and 65 or 75% by weight, based on the respective copolymer, of a macromonomer based on polymethyl methacrylate or a methyl methacrylate/2-hydroxyethyl methacrylate copolymer each with a terminal methacryloyl group.